--- /dev/null
+/*
+ * Stack trace management functions
+ *
+ *  Copyright (C) 2009 Helge Deller <deller@gmx.de>
+ *  based on arch/x86/kernel/stacktrace.c by Ingo Molnar <mingo@redhat.com>
+ *  and parisc unwind functions by Randolph Chung <tausq@debian.org>
+ *
+ *  TODO: Userspace stacktrace (CONFIG_USER_STACKTRACE_SUPPORT)
+ */
+#include <linux/module.h>
+#include <linux/stacktrace.h>
+
+#include <asm/unwind.h>
+
+static void dump_trace(struct task_struct *task, struct stack_trace *trace)
+{
+       struct unwind_frame_info info;
+
+       /* initialize unwind info */
+       if (task == current) {
+               unsigned long sp;
+               struct pt_regs r;
+HERE:
+               asm volatile ("copy %%r30, %0" : "=r"(sp));
+               memset(&r, 0, sizeof(struct pt_regs));
+               r.iaoq[0] = (unsigned long)&&HERE;
+               r.gr[2] = (unsigned long)__builtin_return_address(0);
+               r.gr[30] = sp;
+               unwind_frame_init(&info, task, &r);
+       } else {
+               unwind_frame_init_from_blocked_task(&info, task);
+       }
+
+       /* unwind stack and save entries in stack_trace struct */
+       trace->nr_entries = 0;
+       while (trace->nr_entries < trace->max_entries) {
+               if (unwind_once(&info) < 0 || info.ip == 0)
+                       break;
+
+               if (__kernel_text_address(info.ip))
+                       trace->entries[trace->nr_entries++] = info.ip;
+       }
+}
+
+
+/*
+ * Save stack-backtrace addresses into a stack_trace buffer.
+ */
+void save_stack_trace(struct stack_trace *trace)
+{
+       dump_trace(current, trace);
+       if (trace->nr_entries < trace->max_entries)
+               trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+       dump_trace(tsk, trace);
+       if (trace->nr_entries < trace->max_entries)
+               trace->entries[trace->nr_entries++] = ULONG_MAX;
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);